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                                                                    EXHIBIT 10.1


                           BIOTRANSPLANT INCORPORATED

                            1997 STOCK INCENTIVE PLAN
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1.       PURPOSE

         The purpose of this 1997 Stock Incentive Plan (the "Plan") of
BioTransplant Incorporated, a Delaware corporation (the "Company"), is to
advance the interests of the Company's stockholders by enhancing the Company's
ability to attract, retain and motivate persons who make (or are expected to
make) important contributions to the Company by providing such persons with
equity ownership opportunities and performance-based incentives and thereby
better aligning the interests of such persons with those of the Company's
stockholders. Except where the context otherwise requires, the term "Company"
shall include any present or future subsidiary corporations of BioTransplant
Incorporated as defined in Section 424(f) of the Internal Revenue Code of 1986,
as amended, and any regulations promulgated thereunder (the "Code").

2.       ELIGIBILITY

         All of the Company's employees, officers, directors, consultants and
advisors are eligible to be granted options, restricted stock, or other
stock-based awards (each, an "Award") under the Plan. Any person who has been
granted an Award under the Plan shall be deemed a "Participant".

3.       ADMINISTRATION, DELEGATION

         (a) ADMINISTRATION BY BOARD OF DIRECTORS. The Plan will be administered
by the Board of Directors of the Company (the "Board"). The Board shall have
authority to grant Awards and to adopt, amend and repeal such administrative
rules, guidelines and practices relating to the Plan as it shall deem advisable.
The Board may correct any defect, supply any omission or reconcile any
inconsistency in the Plan or any Award in the manner and to the extent it shall
deem expedient to carry the Plan into effect and it shall be the sole and final
judge of such expediency. All decisions by the Board shall be made in the
Board's sole discretion and shall be final and binding on all persons having or
claiming any interest in the Plan or in any Award. No director or person acting
pursuant to the authority delegated by the Board shall be liable for any action
or determination relating to or under the Plan made in good faith.





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         (b) DELEGATION TO EXECUTIVE OFFICERS. To the extent permitted by
applicable law, the Board may delegate to one or more executive officers of the
Company the power to make Awards and exercise such other powers under the Plan
as the Board may determine, provided that the Board shall fix the maximum number
of shares subject to Awards and the maximum number of shares for any one
Participant to be made by such executive officers.

         (c) APPOINTMENT OF COMMITTEES. To the extent permitted by applicable
law, the Board may delegate any or all of its powers under the Plan to one or
more committees or subcommittees of the Board (a "Committee"). If and when the
common stock, $0.01 par value per share, of the Company (the "Common Stock") is
registered under the Securities Exchange Act of 1934 (the "Exchange Act"), the
Board shall appoint one such Committee of not less than two members, each member
of which shall be an "outside director" within the meaning of Section 162(m) of
the Code and a "non-employee director" as defined in Rule 16b-3 promulgated
under the Exchange Act." All references in the Plan to the "Board" shall mean
the Board or a Committee of the Board or the executive officer referred to in
Section 3(b) to the extent that the Board's powers or authority under the Plan
have been delegated to such Committee or executive officer.

4.       STOCK AVAILABLE FOR AWARDS

         (a) NUMBER OF SHARES. Subject to adjustment under Section 4(c), Awards
may be made under the Plan for up to 750,000 shares of Common Stock. If any
Award expires or is terminated, surrendered or canceled without having been
fully exercised or is forfeited in whole or in part or results in any Common
Stock not being issued, the unused Common Stock covered by such Award shall
again be available for the grant of Awards under the Plan, subject, however, in
the case of Incentive Stock Options (as hereinafter defined), to any limitation
required under the Code. Shares issued under the Plan may consist in whole or in
part of authorized but unissued shares or treasury shares.

         (b) PER-PARTICIPANT LIMIT. Subject to adjustment under Section 4(c),
for Awards granted after the Common Stock is registered under the Exchange Act,
the maximum number of shares with respect to which an Award may be granted to
any Participant under the Plan shall be 100,000 per calendar year. The
Per-Participant limit described in this Section 4(b) shall be construed and
applied consistently with Section 162(m) of the Code.

         (c) ADJUSTMENT TO COMMON STOCK. In the event of any stock split, stock
dividend, recapitalization, reorganization, merger, consolidation, combination,
exchange of shares, liquidation, spin-off or other similar change in
capitalization or event, or any distribution to holders of Common Stock other
than a normal cash dividend, (i) the number and class of securities available
under this Plan, (ii) the


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number and class of security and exercise price per share subject to each
outstanding Option, (iii) the repurchase price per security subject to each
outstanding Restricted Stock Award, and (iv) the terms of each other outstanding
stock-based Award shall be appropriately adjusted by the Company (or substituted
Awards may be made, if applicable) to the extent the Board shall determine, in
good faith, that such an adjustment (or substitution) is necessary and
appropriate. If this Section 4(c) applies and Section 8(e)(1) also applies to
any event, Section 8(e)(1) shall be applicable to such event, and this Section
4(c) shall not be applicable.

5.       STOCK OPTIONS

         (a)      GENERAL. The Board may grant options to purchase Common Stock
(each, an "Option") and determine the number of shares of Common Stock to be
covered by each Option, the exercise price of each Option and the conditions and
limitations applicable to the exercise of each Option, including conditions
relating to applicable federal or state securities laws, as it considers
necessary or advisable. An Option which is not intended to be an Incentive Stock
Option (as hereinafter defined) shall be designated a "Nonstatutory Stock
Option".

         (b)      INCENTIVE STOCK OPTIONS. An Option that the Board intends to
be an "incentive stock option" as defined in Section 422 of the Code (an
"Incentive Stock Option") shall only be granted to employees of the Company and
shall be subject to and shall be construed consistently with the requirements of
Section 422 of the Code. The Company shall have no liability to a Participant,
or any other party, if an Option (or any part thereof) which is intended to be
an Incentive Stock Option is not an Incentive Stock Option.

         (c)      EXERCISE PRICE. The Board shall establish the exercise price 
at the time each Option is granted and specify it in the applicable option
agreement.

         (d)      DURATION OF OPTIONS. Each Option shall be exercisable at such
times and subject to such terms and conditions as the Board may specify in the
applicable option agreement.

         (e)      EXERCISE OF OPTION. Options may be exercised only by delivery
to the Company of a written notice of exercise signed by the proper person
together with payment in full as specified in Section 5(f) for the number of
shares for which the Option is exercised.

         (f)      PAYMENT UPON EXERCISE. Common Stock purchased upon the
exercise of an Option granted under the Plan shall be paid for as follows:

                  (1) in cash or by check, payable to the order of the Company;



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                  (2) except as the Board may otherwise provide in an Option
Agreement, delivery of an irrevocable and unconditional undertaking by a credit
worthy broker to deliver promptly to the Company sufficient funds to pay the
exercise price, or delivery by the Participant to the Company of a copy of
irrevocable and unconditional instructions to a credit worthy broker to deliver
promptly to the Company cash or a check sufficient to pay the exercise price;

                  (3) to the extent permitted by the Board and explicitly
provided in an Option Agreement (i) by delivery of shares of Common Stock owned
by the Participant valued at their fair market value as determined by the Board
in good faith ("Fair Market Value"), which Common Stock was owned by the
Participant at least six months prior to such delivery, (ii) by delivery of a
promissory note of the Participant to the Company on terms determined by the
Board, or (iii) by payment of such other lawful consideration as the Board may
determine; or

                  (4) any combination of the above permitted forms of payment.

6.       RESTRICTED STOCK

         (a)      GRANTS. The Board may grant Awards entitling recipients to
acquire shares of Common Stock, subject to the right of the Company to
repurchase all or part of such shares at their issue price or other stated or
formula price (or to require forfeiture of such shares if issued at no cost)
from the recipient in the event that conditions specified by the Board in the
applicable Award are not satisfied prior to the end of the applicable
restriction period or periods established by the Board for such Award (each,
"Restricted Stock Award").

         (b)      TERMS AND CONDITIONS. The Board shall determine the terms and
conditions of any such Restricted Stock Award, including the conditions for
repurchase (or forfeiture) and the issue price, if any. Any stock certificates
issued in respect of a Restricted Stock Award shall be registered in the name of
the Participant and, unless otherwise determined by the Board, deposited by the
Participant, together with a stock power endorsed in blank, with the Company (or
its designee). At the expiration of the applicable restriction periods, the
Company (or such designee) shall deliver the certificates no longer subject to
such restrictions to the Participant or if the Participant has died, to the
beneficiary designated, in a manner determined by the Board, by a Participant to
receive amounts due or exercise rights of the Participant in the event of the
Participant's death (the "Designated Beneficiary"). In the absence of an
effective designation by a Participant, Designated Beneficiary shall mean the
Participant's estate.



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7.       OTHER STOCK-BASED AWARDS

         The Board shall have the right to grant other Awards based upon the
Common Stock having such terms and conditions as the Board may determine,
including the grant of shares based upon certain conditions, the grant of
securities convertible into Common Stock and the grant of stock appreciation
rights.

8.       GENERAL PROVISIONS APPLICABLE TO AWARDS

         (a)      TRANSFERABILITY OF AWARDS. Except as the Board may otherwise
determine or provide in an Award, Awards shall not be sold, assigned,
transferred, pledged or otherwise encumbered by the person to whom they are
granted, either voluntarily or by operation of law, except by will or the laws
of descent and distribution, and, during the life of the Participant, shall be
exercisable only by the Participant. References to a Participant, to the extent
relevant in the context, shall include references to authorized transferees.

         (b)      DOCUMENTATION. Each Award under the Plan shall be evidenced by
a written instrument in such form as the Board shall determine. Each Award may
contain terms and conditions in addition to those set forth in the Plan.

         (c)      BOARD DISCRETION. Except as otherwise provided by the Plan,
each type of Award may be made alone or in addition or in relation to any other
type of Award. The terms of each type of Award need not be identical, and the
Board need not treat Participants uniformly.

         (d)      TERMINATION OF STATUS. The Board shall determine the effect on
an Award of the disability, death, retirement, authorized leave of absence or
other change in the employment or other status of a Participant and the extent
to which, and the period during which, the Participant, the Participant's legal
representative, conservator, guardian or Designated Beneficiary may exercise
rights under the Award.

         (e)      ACQUISITION EVENTS

                  (1) CONSEQUENCES OF ACQUISITION EVENTS. Except to the extent
otherwise provided in the instrument evidencing the Award or in any other
agreement between the Participant and the Company, upon the occurrence of an
Acquisition Event or with respect to Options or any other similar Awards only,
upon the execution by the Company of any agreement with respect to an
Acquisition Event, (i) the Board shall provide written notice to the
Participants that all Options then outstanding shall become immediately
exercisable in full as of a specified date (the "Acceleration Date") prior to
the Acquisition Event and will terminate immediately prior to the consummation
of such Acquisition Event, except to the


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extent exercised by the Participants between the Acceleration Date and the
consummation of such Acquisition Event; (ii) all Restricted Stock then
outstanding shall become immediately free of all restrictions; (iii) all other
stock-based Awards all become immediately exercisable, realizable or vested in
full, or shall be immediately free of all restrictions or conditions, as the
case may be.

                  (2) An "Acquisition Event" shall mean (a) any merger or
consolidation which results in the voting securities of the Company outstanding
immediately prior thereto continuing to represent (either by remaining
outstanding or by being converted into voting securities of the surviving or
acquiring entity) less than 50% of the combined voting power of the voting
securities of the Company or such surviving or acquiring entity outstanding
immediately after such merger or consolidation; (b) any sale of all or
substantially all of the assets of the Company; (c) the complete liquidation of
the Company; or (d) the acquisition of "beneficial ownership" (as defined in
Rule 13-d-3 under the Exchange Act) of securities of the Company representing
50% or more of the combined voting power of the Company's then outstanding
securities (other than through a merger or consolidation or an acquisition of
securities directly from the Company) by any "person", as such term is used in
Sections 13(d) and 14(d) of the Exchange Act other than the Company, any trustee
or other fiduciary holding securities under an employee benefit plan of the
Company or any corporation owned directly or indirectly by the stockholders of
the Company in substantially the same proportion as their ownership of the stock
of the Company.

                  (3) ASSUMPTION OF OPTIONS UPON CERTAIN EVENTS. The Board may
grant Awards under the Plan in substitution for stock and stock-based awards
held by employees of another corporation who become employees of the Company as
a result of a merger or consolidation of the employing corporation with the
Company or the acquisition by the Company of property or stock of the employing
corporation. The substitute Awards shall be granted on such terms and conditions
as the Board considers appropriate in the circumstances.

         (f)      WITHHOLDING. Each Participant shall pay to the Company, or
make provision satisfactory to the Board for payment of, any taxes required by
law to be withheld in connection with Awards to such Participant no later than
the date of the event creating the tax liability. The Board may allow
Participants to satisfy such tax obligations in whole or in part in shares of
Common Stock, including shares retained from the Award creating the tax
obligation, valued at their Fair Market Value. The Company may, to the extent
permitted by law, deduct any such tax obligations from any payment of any kind
otherwise due to a Participant.



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         (g) AMENDMENT OF AWARD. The Board may amend, modify or terminate any
outstanding Award, including but not limited to, substituting therefor another
Award of the same or a different type, changing the date of exercise or
realization, and converting an Incentive Stock Option to a Nonstatutory Stock
Option, provided that the Participant's consent to such action shall be required
unless the Board determines that the action, taking into account any related
action, would not materially and adversely affect the Participant.

         (h) CONDITIONS ON DELIVERY OF STOCK. The Company will not be obligated
to deliver any shares of Common Stock pursuant to the Plan or to remove
restrictions from shares previously delivered under the Plan until (i) all
conditions of the Award have been met or removed to the satisfaction of the
Company, (ii) in the opinion of the Company's counsel, all other legal matters
in connection with the issuance and delivery of such shares have been satisfied,
including any applicable securities laws and any applicable stock exchange or
stock market rules and regulations, and (iii) the Participant has executed and
delivered to the Company such representations or agreements as the Company may
consider appropriate to satisfy the requirements of any applicable laws, rules
or regulations.

         (i) ACCELERATION. The Board may at any time provide that any Options
shall become immediately exercisable in full or in part, that any Restricted
Stock Awards shall be free of all restrictions or that any other stock-based
Awards may become exercisable in full or in part or free of some or all
restrictions or conditions, or otherwise realizable in full or in part, as the
case may be.

9.       MISCELLANEOUS

         (a) NO RIGHT TO EMPLOYMENT OR OTHER STATUS. No person shall have any
claim or right to be granted an Award, and the grant of an Award shall not be
construed as giving a Participant the right to continued employment or any other
relationship with the Company. The Company expressly reserves the right at any
time to dismiss or otherwise terminate its relationship with a Participant free
from any liability or claim under the Plan, except as expressly provided in the
applicable Award.

         (b) NO RIGHTS AS STOCKHOLDER. Subject to the provisions of the
applicable Award, no Participant or Designated Beneficiary shall have any rights
as a stockholder with respect to any shares of Common Stock to be distributed
with respect to an Award until becoming the record holder of such shares.

         (c) EFFECTIVE DATE AND TERM OF PLAN. The Plan shall become effective on
the date on which it is adopted by the Board, but no Award granted to a
Participant designated as subject to Section 162(m) by the Board shall become
exercisable, vested or realizable, as applicable to such Award, unless and until
the Plan has been


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approved by the Company's stockholders. No Awards shall be granted under the
Plan after the completion of ten years from the earlier of (i) the date on which
the Plan was adopted by the Board or (ii) the date the Plan was approved by the
Company's stockholders, but Awards previously granted may extend beyond that
date.

         (d) AMENDMENT OF PLAN. The Board may amend, suspend or terminate the
Plan or any portion thereof at any time, provided that no Award granted to a
Participant designated as subject to Section 162(m) by the Board after the date
of such amendment shall become exercisable, realizable or vested, as applicable
to such Award (to the extent that such amendment to the Plan was required to
grant such Award to a particular Participant), unless and until such amendment
shall have been approved by the Company's stockholders.

         (e) STOCKHOLDER APPROVAL. For purposes of this Plan, stockholder
approval shall mean approval by a vote of the stockholders in accordance with
the requirements of Section 162(m) of the Code.

         (f) GOVERNING LAW. The provisions of the Plan and all Awards made
hereunder shall be governed by and interpreted in accordance with the laws of
the State of Delaware, without regard to any applicable conflicts of law.




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